The compound disodium cromoglycate (Intal), which inhibits the release of spasmogens from antigen-antibody reactions, is effective in the treatment of asthma and other allergic diseases. Numerous articles have been published which report the clinical results obtained with disodium cromoglycate. In addition, the following U.S. Pats. have issued describing disodium cromoglycate and related compounds: Nos. 3,567,741; 3,706,768; 3,705,945; 3,419,578; 3,686,412; 3,671,625; 3,728,688; 3,673,218; 3,686,320; and 3,634,582. The compound 1-oxo-1H-2-benzothiopyran-3-carboxylic acid has been described by Dijksman and Newbold, J. Chem. Soc., 1951, 1213, and related compounds have been described by J. N. Chatterjea, et al., J. Indian Chem. Soc., 44, 697 (1967).